Improvement in sewing-machines



D. W- CLARK.

Sewing Machine.

Patented May 3, 1859.

UNITED STATES PAT NT OFFICE.

D. WV. .CLARK, OF BRIDGEPORT, CONNECTICUT.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 23,823, dated May 3, 1859.

To all whom it may concern.-

Be it known that I, D WV. CLARK, of Bridgeport, Fairfield county, State of Connecticut, have invented a new and useful Improvement in Sewing-Machines; andI do hereby declare that the following isa full, clear, and exact description of my invention, which will enable any person skilled in the art to make and use the same.

In the accompanying drawings, Figure 1 is a plan view, in part sectional. Fig. 2 is an end sectional elevation; Fig. 3, a cross-see. tional elevation of the feeding-wheel; and Fig. 4 a sectional elevation of the tension parts, and general side view.

Similar letters of reference in all the figures indicate the same parts. 7

A is the base of the frame, which may be made in the usual manner. B isthe table upon which the fabric to be sewed rests. The usual aperture for the passage of the needle is made in the table; also an opening through which the teeth of the feed-wheel C pass, so as to touch the under surface of the, cloth. The "latter is pressed down upon the surface of the wheel by means of the usual spring foot or pad. The wheel C rotates upon a pivot or axis, D, which is made in the form of a screw, and passes through the wheel C and secures the same to a block, E. This block is fastened to the under side of the table. The wheel C is provided with a shoulder, b, in which is a groove, (1/. The shoulder]; passes through the end of a lateral lever, F. A spring, G, is attached to the outer end of the lever F, said spring extending through an aperture in that portion of the lever which girdles the shoulder b to the groove a. The extremity of spring G is provided with a beveled block, 0, which fits into said groove a. Spring G thus serves as a pawl, and by bearing into the groove a sufficient friction is produced by throwing up the end of lever F to cause the wheel C to rotate in direction of arrow 1'. \Vhen the end of the lever is thrown down the block 0 slips in the groove a and does not carry the wheel C backward. To insure the rest of wheel C during the descent of the lever F, a coil-spring, d, is placed upon the axis 1), which spring bears upon the head of the axis at one end, and upon the wheel C at the other, thus pressing one end of the wheel against its block E with a slight friction. The necessary up-anddown motion of the lever F to give rotation to the feed -wheel is obtained by having an inclined slot, f, cut

in the extremity of the lever F, which slot receives the end of avibrating lever, H, pivoted at g to the frame A. The end of the lever H, which fits into slot f, is composed of a separate piece, h, and pivoted to H. By thus having the piece h pivoted the said piece'remains in the slotf during the up-and-down motion of i could not then remain in the slot during both the up and down strokes of lever F; but by my arrangement the lever H gives both the up and down motion of F in a sure and certain manner, without any springs or other uncertain parts.

The tension of the thread is regulated by I having the spool J placed between two center pieces, z i, which are movable upon the rod I, as shown in Fig. 4. The upper center piece '5 is prevented from slipping off from the rod I by thehead thereof. The rod I passes through a hole in the needle-arm or other convenient part of the frame, and is adjusted to any desired height or position by the set-Screwj. A spring,

7c, of spiral form, is placed between the bottom of the lower center piece 5, and the top of the needle-arm, which spring passes up against the bottom of center piece 6 with a force that depends upon the relative height of adjustment of rod I. WVhen it is desired to increase the tension, it is only necessary to slacken the screw j and depress the rod I.- The spring 70 will thus be caused to press with greater force upon the center piece 1' and prevent it from so easily revolving and carrying the spool. If the tension is to be diminished, the screw j is loosened and the rod I raised, when the spring 70 will press with less force upon the center piece z, and thus allow the spool J to revolve more easily; I

A common method of arranging the tension is to have the spool-rod fixed and a screw thread out upon its upper end to receive a nut which presses a spring upon the spool or its center piece. This plan necessitates the having of a projecting screw and spring above the spool, which besides being unsightly, leaves a point upon which the goods are liable to catch in handling and become torn. My improve- -1nent leaves no fprojection, but permits a rounded elegant finish of the part above the spool, and the goods are not liable to injury;

Iclaim as my invention, and as an improvement on my patent of August 31, 1858- The combination and arrangement of mechanism herein described for the purpose of controlling the feed-Wheel in the manner set forth.

Bridgeport, Connecticut, November 8, 1858.

D. W. CLARK.

Vitnesses:

J. CURTIS, SAMUEL IWoYLn. 

